Budesonide is a non-halogenated glucocorticosteroid available in metered dose inhaler and breathe activated formulations currently marketed in Europe, Asia, Australia and Canada. The budesonide turbuhaler is in clinical Phase 3 development in the US. Budesonide has also been formulated in a nebulizing suspension and is available in Europe, Australia, and Canada. Data suggest that budesonide nebuizing suspension may represent an alternative form of inhalation therapy for asthma in children who are unable to effectively use a metered dose inhaler or the breath activated turbuhaler. Furthermore, budesonide nebulizing suspension may also represent an alternative to oral steroids in children who may require this form of therapy. This clinical study proposes to investigate the relative efficacy and safety of three dose levels of budesonide nebulizing suspension once a day as compared to placebo in children with asthma between the ages of 4 and 8 years for a period of 12 weeks.